The use of brushless fan motors is known in the automotive industry. These are used for applications such as cooling fans for cooling down the internal combustion engine and for cooling fans for air conditioning and interior ventilation systems.
With known brushless fan motors with internal rotors, both rotor and stator and also the motor electronics are enclosed in a housing between a front and a rear end shield. The fan wheel is arranged outside the housing and is connected to the fan motor via the drive shaft. The drive shaft in this case is guided in the front and in the rear end shield of the housing.
The German utility model 94 04147 U1 discloses an axial fan in which the fan wheel is connected directly to a rotor embodied as an internal rotor of the fan. On the face of the rotor arranged opposite the fan wheel an additional smaller fan wheel is provided for creating an air flow through an air gap formed by stator and rotor, which cools the windings of the rotor and of the stator and avoids deposits of moisture in the air gap of the motor.
German application DE 42 14 160 A1 describes a fan in which the fan wheel carries the rotor of the drive without a drive shaft being used for this purpose.